Spring Boot test

For overview of Mockito see the mockito memory aid on this page.

@MockBean & @Autowired

@MockBean allows to addd a mocked bean to the spring application context. So when you use @Autowired on another class it will load the mocked bean if it was referenced. It is a convenient way to work with mocks, because you do not need to mock every field of the (autowired) class under test. Just the ones you need to behave differently.

MockRestServiceServer

The MockRestServiceServer allows to intercepts the calls to a RestTemplate. It is handy to mock calls to external APIs.

@InjectMock & @Mock

You may want to avoid using @InjectMock, because it fails silently without an exception, which is kind of annoying. Alternatively use @MockBean when using spring or just call the constructor of the class under test and mock every parameter of it with @Mock. Remember that a class which is instantiated by a constructor call is not spring managed.